George RR Martin wants next Game of Thrones book The Winds of Winter finished by July 2020

The author of the Game of Thrones saga has revealed when he wants the next book in the series to be completed.

The latest entry in A Song of Ice and Fire was A Dance with Dragons, released nearly eight long years ago in July 2011.

Ever since, fans have been hungry for the next chapter, The Winds of Winter, in the now legendary saga that led to the television behemoth Game of Thrones.

After giving out dates for when he wanted the book done by that were eventually passed, author Geroge RR Martin said it would be done when it was done.

But he has now given a new clue for when he wants the sixth book in the series to be finished.

On Wednesday (NZ Time), Martin wrote on his blog that he was planning a trip to Wellington in July 2020 to attend the World Science Fiction Convention.

He said he didn't want to come to New Zealand to write out of fear it would "distract me entirely too much", but when he does arrive that shouldn't matter because The Winds of Winter should already be completed.

"If I don't have The Winds of Winter in hand when I arrive in New Zealand for worldcon, you have here my formal written permission to imprison me in a small cabin on White Island, overlooking that lake of sulfuric acid, until I'm done," he wrote.

"Just so long as the acrid fumes do not screw up my old DOS word processor, I'll be fine."

Demand for the next entry is extremely high with the television series winding up this week.

Earlier, Martin said the book series would have a different ending to the show with many characters in the literary material that wasn't on the show - and vice versa.

But that ending could also be long off. There will be a seventh entry, A Dream of Spring, after The Winds of Winter, and Martin says he hasn't even begun it.